Re: [RFC][PATCH] tracing: Deprecate auto-mounting tracefs in debugfs

[Sebastian Andrzej Siewior]

On 2025-06-17 20:00:23 [+0200], Peter Zijlstra wrote:
> If I have to edit the mount table, I'll just keep it at /debug/tracing/.
> Tracing is very much debug stuff anyway. While I knew there was tracefs,
> I never knew there was another mount point.
> 
> Just annoying I now have to add two entries to every new machine.. Oh
> well.

I don't know what you run but since Debian 11/ Bullseye (v5.10) this happens
more or less on its own. systemd has the proper mount units:
| # mount | grep trace
| tracefs on /sys/kernel/tracing type tracefs (rw,nosuid,nodev,noexec,relatime)
| # ls -lh /sys/kernel/debug/tracing/ > /dev/null
| # mount | grep trace
| tracefs on /sys/kernel/tracing type tracefs (rw,nosuid,nodev,noexec,relatime)
| tracefs on /sys/kernel/debug/tracing type tracefs (rw,nosuid,nodev,noexec,relatime)

This of course doesn't work if you manually mount it to /debug. While a
symlink would work, you still have to touch the boxes.

Sebastian